In aircraft construction, whenever developing lighter and safer aircraft, monitoring the structural integrity (SHM) is also always an essential field, the substantial aim of which is to monitor and observe damage to structures. Detecting damage and measuring the severity thereof are critical features for subsequent decision-making. In this case, the development of structures based on materials other than metals requires modified monitoring and damage-detection methods.
Since more and more aircraft or spacecraft parts were being made of fiber-reinforced plastic materials, approaches for assessing damage to such structures had to be developed, these including, inter alia, ultrasonic measurement methods, thermography, electrical potential measurements and vibration-based tests.
Due to the dimensions of aircraft and spacecraft in particular, the costs associated with the known methods are substantial and these methods are generally only suitable for monitoring during maintenance intervals, and not during operation of the aircraft or spacecraft.
Another method proposes analyzing the thermal behavior of fiber-reinforced plastic materials (CFRPs), which appears to be promising, since it is possible to record how external influences can act on the quality of heat dissipation in the material, for example, in a more cost-effective manner, and this can be used to make statements relating to damage. However, introducing thermal sensors into the matrix of the plastic material of the component in question during maintenance/inspection renders the component unusable in principle, and data from the operation of the component cannot be obtained by the sensors. Lastly, it would be desirable to be able to make statements relating to the production process of the plastic component without having to provide an additional costly test setup for this.